Liquid and vapor separating pump



April 1, 1947. R.l R. CURTIS 2,418,221

LIQUID AND VAPOR SEPARATING PUMP .Filed Oct. '50, 1944 2 SheAets-Sheet 1 Russell Curlis April l, 1947. R CUR-ns 2,418,221

LIQUID AND VAPOR SEPARATING PUMP Filed Oct. 30, 1944 2 Sheets-Sheet 2 Eig-4 'Rwezz Rear-tis Patented Apr. 1, 1941 LIQUID AND VAPOR sEPAnArlNG PUMP Russell R. Curtis, Dayton, Ohio, .assig'nolh'- to Curtis Pump Company, Dayton, Ohio, a corporation of (Jhio` Appuatimi october ao, 1944, serial No. $60,940

This invention relates to devices for separating liquids and vapors or gases.

vSpecilically the invention deals with liquid and y vapor-separating booster pumps especially adapted for aircraft fuel systens, to prevent vapor lock even at very high altitudes,

According to this invention, pump andmotor units are provided for insertion in airplane fuel tanks. The pumps have impellers equipped with a ring of spaced pumping vanes. The inner ends of the vanes surround an axial passageway. The spaces between the vanes form pumping channels. 'I'he axial passageway-ls in full open communication with gasoline or other liquid contained in the tank. The vanes throw the liquid material radially by centrifugal force into a pumping chamber. This radial discharge of liquid through the pumping channels, of course, creates way defined by the inner ends of the vanes.v The inner ends of the vanes serve asv agitators, and

liberate occluded gases and vapors in the liquidy is reduced when the plane climbs to high alti tudes. As the climb in altitude progresses, vapor forms and gathers at the inner edges of the impeller vanes in a gradually widening ring. This widening ring of vapor can ultimately spread all the way tothe outer ends of the vanes through the pumping channels between the vanes and, of course, when this occurs, the pump becomes gas-bound and fuel delivery to the airplane engine will stop.

According to this invention, however, the impeller Yanes are equipped with passages for va- -por-rlch liquid to vent the bubbles of gas and vapor from the inner edges of the vanes, back to the interior of the tank. The vanes are preferably hollow and have slotted inner edges in full communication with the periphery of the axial passageway. These hollow vanes will collect bubbles of the gases and vapors liberated from the liquid in the axial passageway and will immediately vent the bubble-rich liquid back to the tank before lany ring of vapor can form around the axial passageway. The hollow impellerA vanes thus vent the gases and vapors out of the pump as soon as the gases and vapors are liberated from the liquid, and the devices of this invention are much more efiieient than heretoan outward flow from the axial passage-l 18 Claims. (Cl. 10S-113) fore-known vapor and liquid separating pumps. I It is, then, an object of the invention to provide vapor and liquid-separating. .devices with hollow vanes for directly venting vapors and gases outof the device as soon 'as the vapors and gases are liberated from the liquid acted onby the devices.

A further object of the invention is to provide an impeller for vapor and liquid separating pumps which has a plurality ofpumping blades each provided with a passageway therethrough.

A still further object of the invention is to provide pump and motor units for aircraft fuel systems which more effectively separate gases and liquids than heretofore-known pumps by venting bubble-rich liquid through the pumping vanes asI soon as the vanes create the bubbles.

A stillfurther object of the invention is to provide submerged-typeboster pumps with hollow impeller blades for venting gases and vapors out of the pumps.

A still further objezt of the invention is to provide vapor and Yliquid-separating pumps with centrifugal impellers having passaged blades for discharge of gases out 'of the pump, and lmeans for pumping bubble-rich liquid through the blades.

Other and further objects of the invention will be lapparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of preferred examples only, illustrate two embodiments of the invention.

On the drawings: Figure 1 is a broken fragmentary vertical cross-sectional view, with parts in sidefelevation, Iof a submerged pump and motor unit according to this invention mounted in a tank.

Figure 2 is an enlarged bottom plan view of the pump impeller taken along the line II-II of Figure 1, wherein one group of the blades 1s omitted, another group of the blades.` is shown in horizontal cross section, and' a third group of .blades is shown in bottom plan.

Figure 3 is an enlarged vertical cross-sectional view taken along the line III-III of Figure 2.

VFigure 4 is a view similar to Figure 1, but illustrating a modified form of unit acsording to this invention.

Figure 5 is an enlarged top plan view of the pump carsing and impeller with parts in horizonnates generally a fuel tank having a bottom wall Ita with a large aperture Ib therein. The tank I3 will hereinafter be referred to as an airplane fuel tank which is vented to ambient air. but it should be understood, of course, that an? time` of container can be used for the units of this I invention. 4

A -mounting Aring .Il is mountedk on the bottom wall Ita of the tank and surrounds the opening IIib.

A pump and electric motor unit I2 is submerged in the tank I0. The unit I2 lhas a mounting base I3 with a peripheral flange I3a therearound underlying the tank' wall Ina. Cap screws I4 are passed through the flange I3a and are threaded into the mounting ring I I to secure the mounting base i3 to the tank. A gasket Il is interposed between the flange I3a and the bottom Illa of the tank to seal the opening IIIb.

' The mounting base I3 is connected through ribs such as I6 with a ypump casing I1 defining an annular volute chamber I3 around a central open-ended passageway I9. The volute chamberI3 discharges through a passageway 20 in to an upstanding passageway l2I defined by a` tubular boss member 22 whichv isintegral with the base I3 and is spaced laterally from the casing I1. As shown, the tubular boss 22 extends beyond the bottom of the base I3 and receives a conduit fitting 23 in the lower end thereof. A cap 24 closes the top end of the'base, and a single bolt 2l is passed through the tting 23 and threaded into the cap 24 to clamp the fitting and cap on the. opposite ends of the base. Gaskets-26 are interposed between the ends of the tubular boss 22 and the cap and conduit fitting.

Liquids from the volute chamber 3 are( thus propelled through the passageway 20 into the passageway 2i and thence through the conduit fitting 23 to the f uel line of an airplane fuel system. This fuel line customarily supplies the engine-.driven main fuel pump of the system (not shown).

The mounting base I31has a separate closure plate 21 secured thereon by means of cap screws 33 and maintained in sealed relationship therewith by a gasket 29. This closure plate 21 is beneath the bottom wall Illa of the tank and provides a sump S for the tank. This sump can `be drained through a plug 30 threaded into the plate 21.

A throat ring 3i is secured to the bottom face of the casingl1 by means of cap screws 32, and defines an inlet I for the pump. This inlet I communicates freely with the sump s and, o f course, the sump S communicates freely 4with the interior of the tank I0.

enana:

Hollow blades or vanes 49 depend from the nange 31d. These vanes are arranged in spacedv -parallel relationship as best shown in Figure 2.

channels 4I are provided between the vanes. y

The rounded inner edge 43a of each vane has a slot 40o extending from the bottom to the top thereof, as'best shown in Figure 3. The vanes preferably have bottom walls 43d closing the bottoms of the slots 4IIc and overlying the throat ring 3I in closely spaced relation. v

While the inner ends 49a of the vanes extend along a straight vertical path, the outer ends of the vanes. as best shown in Figure l, diverge outwardly from the relatively narrow bottoms 43d along 'soping wall portions 43e to outtumed flanges 40f overlying the throat ring 3I as best shown in Figure 1. These flanges 43! thus extend into the gap 39 and upstanding walls 49g connect the flanges 40j with the peripheral portion'of the flange 31d. 'I'he vanes thus have elongated inner edges, and increase in width from their bottom ends to wide top portion which project through the gap 39 to the volute chamber I3. Each hollow vane 49 has. a chamber 42 therein extending from the.top to the bottom thereof and open along its length through the slot 40e.

The ange- 31d has slots 43 therein aligned with the open tops-of the chambers 42. Thesey way I9 thereby venting the inner edge of Aeach vane to the side of the pumpcasing opposite the inlet I thereof.

A screen 44 surrounds the pumpunit. to prevent flow of solid material into the pump.

- The unit of Figures 1 to 3 thus receives screened liquid from the tank III into the sump 8 thereof, and liquid from this sump B flows freely through the pump inlet I into the chamber surrounded by the pumping vanes 40. These pumping vanes centrifugally discharge the liquid into the pumping chamber or volute chamber I 3 and thence thrugh the passageway 20 into the pas- The casing I1 has an upstanding leg 33 thereon carrying` a base 34 for a motor casing 35. The

sageway 2| and conduit fitting 23. The liquid is thrown by centrifugal force through the pumping channels 4I between lthe vanes 43 into the pumping chamber I3.

The innner ends 40a of the vanes 43 agitate the motor in the casing 35 hasa drive shaft 33 -'ex- 60 liquid 111 the chamber provided above the inlet tending through the base 34 and carrying theu impeller 31 for the pump. The impelleil 31 has. a hub 31a fitting over the shaft 39 and secured on the shaft by,means of a nut 33 which is threaded on the shaft. A flange 31h extends outwardly from' the bottom ofthe hub 31a and a skirt 31e depends from the periphery ofthe ange 31a. The bottom ofthe skirt 31e merges `into an-outturned flange 31d which projects into ar annular gap 39 connecting the passageway I3 with'the volute 'chamber I3. The gap 39 is provided immediately above the throat ring 3i.

An upstandlng collar 31eis provided on'. the ange 31d. This collar has close-runningl clearance withV the wall defining thepassageway I9.

' pass through the slots 4Iic into the vane chambers 42 and,l being Llighter than the surrounding solid liquid, the bubble-rich liquid will iiowl through theslots 43 into the passageway I9 and out of the open top of the pump. Individual 5 now passages thus vent the vapors from the inner ,end of eachpumping vane where the vapors are separated from the liquid and discharge the vapors` at points `remote from the pump inlet.

,In the embodiment of the invention disclosed in. Figures 4 and 5, parts corresponding with lparts described in Figures 1 to 3 have been marked with the same reference numerals.

Asshown in Figure 4, the pump casing I1 has a cover 50 thereon connected thereto by means of bolts 5I and maintained in sealed relationship therewith by a gasket 52. This cover 50 dennes an annular chamber 53 above the pumping chamber I8, and a seal ring 54 is secured on the casing I1 by means of screws 55, to separate the chambers I8 and 53.

The impeller 31 has the hub 31a, flange 31h, skirt 31o, and iiange 31d all as described inl connection with the impeller 31 of Figures 1 to 3, but the peripheral portion of the ange 31d has a thickened rim 5'6 providing a side wall having close-running clearance with the sealing ring 54. The hollow vanes 40 are substantially the same as the vanes 40 described in Figures 1 to 3, but the shallow end walls 40g thereof underlie the thickened portion 56, and these end walls are thus intermediate the top and bottom of the vanes since the inner edges of the vanes extend to the flange 31d. l

A ring 51 is secured in the cover 50 and has a central aperture 51a receiving the skirt 31e of the impeller in close-running clearance relationship therewith. The ring 51 denes a chamber, 58 around the lower portion ofthe skirt 31o and above the flange 31d. This chamber 58 communicates through the slots 43 in the flange 31d with the chambers provided in the vanes 40.'

Upstanding pumping vanes 59 are provided on the ilange 31e outwardly from the slots 43 thereof, and these vanes underlie the ring 51 to provide pumping channels .60 connecting the chamber 58 with the chamber 53. The chamber 53 is vented to the interior of the tank I through slots 6I provided in the top of the cover. The chamber 53 thus is in free communication with the interior of the tank I0 on the side of the pump remote from the inlet I thereof.

In operation, the modied pump unit of Figures 4 and 5 acts the same as the unit described in Figures 1 to 3 except that a separate collecting chamber is provided for the gases `-discharged from the blade chambers. The gases or vapor rich liquid` in this collecting chamber is centrifugally impelled out of the chamber by means of separate pumping vanes B which discharge the vapor rich liquid back to the interior of the` tank through the chamber 53 and vent slots 6I.

The pump of Figures 4 and 5-provides for the positive impelling of bubble-rich liquid through the hollow vanes, since pumping vanes 59 are provided for this purpose. e

than necessitated by the scope of the appended Claims; d j

Lclaim as my invention:

1. A submerged type pump and motor unit for separating gases from liquids which comprises a mounting` base, a pump casing carried by said base having a central inlet and annular pumping chamber, an upstanding open ended hollowl boss on said base communicating with said pumping chamber and deiining an outlet passageway for the pump adapted to discharge out of either end thereof, a cover plate on said lbase cooperating therewith to dene a sump below the pump inlet, a motor unit mounted on said pump casing in spaced relation therefrom. said motor unit having a shaft depending into the pump casing, a pump impeller secured on said shaft and having a ring of circumferentially spaced pumping blades denning pumping channels connecting the central inlet with the annular `pumping chamber, and each of said pumping blades having a passageway therethrough venting the inner edge thereof with the outside of the pump.

2. A device for separating vapors from liquids which comprises a casing having a. central passageway therethrough and dening an annular pumping chamber around the passageway a in communication with said passageway, a. pump impeller in said passageway having a ring of peripherally spaced hollow pumping blades therearound dening pumping channels therebetween which connect the passageway with the pumping chamber, and each of said blades having a passage connecting the inner edge thereof with the upper end of the passagev to discharge vapors formed adjacent the inner edge of the blade.

3. A device vfor pressuring fully liquid material from a source of liquid which comprises a pump lassembly having an open-ended passage with a bottom inlet end and an annular outlet intermediate the top and bottom of the passage, means defining an annular pumping chamber adapted to receive iiuid from said passageway ranged for centrifugally discharging liquids from From the above descriptions, it will be clear the passageway into the pumping chamber, and said hollow vanes having open inner ends communicating along their lengths with said passageway together with discharge outlets communicating with the upper end of the passageyway whereby vapors liberated by said vanes can flow through the vanes to be discharged out of the pump.

4. A liquid and vapor separating device comprising a casing having an annular pumping chamber with a central inlet and'a peripheral outlet, an impeller mounted in said casing having a ring of hollow pumping vanes thereon arranged for centrifugally discharging liquid from said inlet through said pumping chamber to said outlet,` and each of said vanes having an inlet opening on the inner end thereof and an outlet opening on the top end thereof whereby gases and vaporsliberated by the vanes adjacent the inner vends thereof will ilow through the vanes to the outside of the pump along individual paths separate from the liquid ow path.

` 5. A gas and vapor separating pump Vwhich comprises a mounting base having a peripheral having a central inlet passageway and an anl 7 nular pumping chamber around said passageway in communication therewith, an upstanding tubular boss member on fsaid base communi-- cating with said` pumping chamber to receive liquids therefrom, a, .motor/casing supported on said pump casing in spaced relation thereabove. a motor shaft depending from said-x`notor cas- V ing. an impeller having a hub secured on'said shaft together with a flange extending across said-central passageway of the pump casing and having openings at spaced intervals therearound, and a plurality of pumping vanes depending,

ing slotted and said pumping vanes having pasl sages therethrough communicating with the opening in said flange for conveying gases and vapors from the inner edges of the vanes out of the pump to prevent the pump from becoming -gas-bound. g

-6. A .gas and vapor separating pump which comprises a pump casing having a central passageway and an annular pumping chamber therearound, a pump impeller in saidpassageway, a ring of pumping lvanes open at the inner ends of said vanes and on said impeller for centrifugally discharging uidsl into said pumping chamber, said vanes having inner ends surrounding the central passageway, and passages through said vanes connecting the inner ends of the vanes with the upper portion of the passageway to accommodate flow of vapors therethrough.

7. Avapor separating pump comprising a pump casing having a central passage therethrough and vannular pumping chamber surrounding said passage in communication therewith around the entire inner periphery thereof, an impeller having a flange extending across said passageway, hollow pumping vanes depending from said :dange arranged for centrifugally discharging fluids from said passageway through said pumping chamber, said pumping vanes having slotted inner edges foragitating liquids in said passage- Way to liberate-bubbles of gas and vapor therefrom, and said flange having openings therein for passage of bubbles of gas and vapor from the hollow interiors of lthe blades out of the PUmD- 8. A vapor separating pump which comprises a casing having an annular pumping chamber with an inner peripheral inlet and an outer peripheral-outlet. an impeller in said casing having a ring of pumping vanes arranged for centrifugally discharging vliquids through said inner peripheral inlet, said pumping vanes having passages therethrough connecting the inner edges of the vanes with a top outlet, means in said casing defining a receiving chamber for fluids discharged through said top outlet, and additional vanes for centrifugally discharging the fluids in said receiving chamber out of the casing.

9. A vapor and liquid separating pump which comprises a pump casing having a central inlet,

,an annular pumping chamber communicating with said inlet around the innerperiphery thereof and having a peripheral discharge outlet, said 8 an additionalset of vanes on said impeller for Vcentrifugally discharging fluids from said collecting chamber to said second annular chamber, and said first mentioned pumping vanes having passages therethrough connecting the inner edges thereof with said collecting chamber' whereby gases and vapors liberated at saidinner ends of the pumping vanes will flow through said passages in the vanes and be discharged `out of said pump by said additional vanes.

l0. A pump comprising "a casing having a bottom inlet, an annular pumping chamber and a peripheral outlet, an. impeller having a ring of hollow pumping vanes disposed in saidcasing and arranged for pumping fluids from the inlet through said pumping chamberto theoutlet,\said hollow vanes having slots 'along the inner edges thereof and outlets along the top ends thereof,

and an additional set of vanes on said impeller arranged for pumping gases and vapors through I said hollow vanes.

l1. In a vapor separating pump the improvement which comprises an impeller having a ring of hollow pumping vanes defining pumping channels therebetween, said hollow `vanes having an inlet adiacent their inner ends and an outlet at 'the tops thereof, and a second set of pumping` vanes on said impeller above said pumping blades for flowing fluids through the hollow portions of the vaines.

12. A pump impeller comprising a hub memcating with the tops, of the hollow portions of Y said vanes.

' 13. A pump impeller comprising a body memu l ber having a central hub, a first outturned flange at the end of said hub, a depending skirt on said i'irst flange, a second outturned flangeon the end of said skirt and a ring of slots through said second flange, and a ring of hollow pumping vanes depending from said second flange having slotted inner edges and open tops communicating with said slots. A if 14. A pump impeller which comprises a body member having a central hub portion and a radial flange, a ring of hollow pumping vanes depending from said flange, said pumping vanes having slotted inner ends and open tops, and said radial flange having openings therein aligned with the open tops of said hollow vanes charge vapors out of the vanes.

15. -A pump impeller comprising a body member having a radial flange, a, ring of hollow pumping vanes depending from said flange. said hollow pumping yvanes having open inner edges and open tops, and said radial flange having openings therethrough for receiving fluids from the open tops of the pumping vanes.

16. A pump impeller comprising a body mem-lv ber having an outturned flange. a first ring of` pumping vanes depending from one face of said flange, a second ring of pumping vanes extending upwardly from the other face of said flange, the pumping vanes of said first ring being hollow and having inlet openings along their inner edges and outlets along the top endsthereof, andsald flange having openings A.therethrough aligned with said outlets and positionedinside of said Second ring 0fA pumping vanes"v the pumping chamber, means in said` casing denning a collecting chamber above said impeller.

17. An impeller` biade v'which immenses" a u streamlined curvedvane havingan" open-'toma rounded inner edge portion and tapering side walls converging from said rounded inner edge portion, said inner edge portion having a slot along a length thereof, and said vane having a passageway therethrough connecting said slot with the open top of the vane.

18. A pumping blade which comprises a hollow streamlined curved centrifugal pumping vane having a. rounded inner edge and side walls con--` verging from said inner edge, a bottom wall on said vane, a'n outer edge wall on said vane, an open top on said Vane, and said inner edge of the Vane having a slot therein whereby the interior of said vane dened by said walls has an inlet in the inner edge and an outlet in the top 15 thereof.

RUSSELL R. CURTIS.

REFERENCES CITED UNITED STATES *PATENTS Number Name Date 2,344,835 Stalker g Mar. 21, 1944 FOREIGN PATENTS Number Country Date '1,401 Netherlands Allg. '15, 1922 833,532 French Oct. 24, 1938 

